Litologías manganesíferas del área central de Ossa-Morena (SW de Badajoz)
- Jiménez Millán, Juan
- Ruiz de Almodóvar Sel, Gabriel
- Velilla, Nicolás
ISSN: 0213-683X
Année de publication: 1992
Número: 12
Pages: 46-49
Type: Article
D'autres publications dans: Geogaceta
Résumé
Mangenese lithologies from Oliva de la Frontera area occur in the Cumbres-Hinojales unit (Ossa-Morena South-Central Belt) within a Lower Ordovician age volcanosedimentary sequence. Petrographic study allows to differentiate six Mn-Fe lithologies: Mn-crystal tuffs, Mn-shales, cotfcules, Mn-pyroxenoid rich rocks, braunite layers and hematite layers. Al/(Al+Fe-f-Mn) and Na/(Na+K) discriminating ratios support the above classification. Geologic, mineral, textural and geochemical data provide dues about the mixture process among volcanic, terrigene and chemical materials that originated the protolliths o f the metamorphic manganese lithologies